loop6: rw=524288, sector=1056, nr_sectors = 16 limit=16 syz.6.302: attempt to access beyond end of device loop6: rw=524288, sector=8, nr_sectors = 16 limit=16 ================================================================== BUG: KASAN: use-after-free in memcpy_to_page include/linux/highmem.h:403 [inline] BUG: KASAN: use-after-free in z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346 Read of size 4096 at addr ffff0000f88b0000 by task syz.6.302/5899 CPU: 0 PID: 5899 Comm: syz.6.302 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0xfc mm/kasan/report.c:524 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x258/0x290 mm/kasan/generic.c:189 memcpy+0x48/0x90 mm/kasan/shadow.c:65 memcpy_to_page include/linux/highmem.h:403 [inline] z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:434 z_erofs_decompress_pcluster fs/erofs/zdata.c:1159 [inline] z_erofs_decompress_queue+0x100c/0x1b40 fs/erofs/zdata.c:1240 z_erofs_runqueue+0x152c/0x16cc fs/erofs/zdata.c:1603 z_erofs_read_folio+0x2d8/0x5c8 fs/erofs/zdata.c:1693 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 filemap_update_page mm/filemap.c:2575 [inline] filemap_get_pages mm/filemap.c:2689 [inline] filemap_read+0x12cc/0x2104 mm/filemap.c:2759 generic_file_read_iter+0xf8/0x5c4 mm/filemap.c:2941 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x3d4/0x7f0 fs/read_write.c:470 ksys_read+0x12c/0x224 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:621 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Allocated by task 5826: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x74/0x430 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x22c/0x308 mm/slub.c:3383 skb_clone+0x190/0x304 net/core/skbuff.c:1660 dev_queue_xmit_nit+0x210/0x994 net/core/dev.c:2334 xmit_one net/core/dev.c:3691 [inline] dev_hard_start_xmit+0xf8/0x8cc net/core/dev.c:3711 sch_direct_xmit+0x210/0x474 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3932 [inline] __dev_queue_xmit+0x13bc/0x3118 net/core/dev.c:4337 dev_queue_xmit include/linux/netdevice.h:3051 [inline] neigh_hh_output include/net/neighbour.h:529 [inline] neigh_output include/net/neighbour.h:543 [inline] ip_finish_output2+0xb98/0x109c net/ipv4/ip_output.c:228 __ip_finish_output+0x1b0/0x448 net/ipv4/ip_output.c:-1 ip_finish_output+0x40/0x264 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip_output+0x3c8/0x568 net/ipv4/ip_output.c:434 dst_output include/net/dst.h:453 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0xc84/0x1674 net/ipv4/ip_output.c:538 ip_queue_xmit+0x5c/0x7c net/ipv4/ip_output.c:552 __tcp_transmit_skb+0x17d8/0x2b88 net/ipv4/tcp_output.c:1405 __tcp_send_ack+0x23c/0x4e8 net/ipv4/tcp_output.c:4059 tcp_send_ack+0x4c/0x68 net/ipv4/tcp_output.c:4065 __tcp_ack_snd_check+0x3b4/0x848 net/ipv4/tcp_input.c:5626 tcp_ack_snd_check net/ipv4/tcp_input.c:5672 [inline] tcp_rcv_established+0xad8/0x1d20 net/ipv4/tcp_input.c:6116 tcp_v4_do_rcv+0x38c/0xa7c net/ipv4/tcp_ipv4.c:1684 tcp_v4_rcv+0x1f2c/0x24cc net/ipv4/tcp_ipv4.c:2115 ip_protocol_deliver_rcu+0x350/0x778 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x250/0x488 net/ipv4/ip_input.c:233 NF_HOOK+0x2dc/0x36c include/linux/netfilter.h:302 ip_local_deliver+0x120/0x194 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:463 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0x8a8/0xb90 net/ipv4/ip_input.c:639 ip_list_rcv+0x394/0x3f0 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5662 [inline] __netif_receive_skb_list_core+0x4e8/0x67c net/core/dev.c:5710 __netif_receive_skb_list net/core/dev.c:5762 [inline] netif_receive_skb_list_internal+0x6f0/0x998 net/core/dev.c:5853 gro_normal_list include/net/gro.h:433 [inline] napi_complete_done+0x258/0x604 net/core/dev.c:6194 gve_napi_poll_dqo+0x120/0x1c4 drivers/net/ethernet/google/gve/gve_main.c:260 __napi_poll+0xb4/0x3f0 net/core/dev.c:6628 napi_poll net/core/dev.c:6695 [inline] net_rx_action+0x514/0xb18 net/core/dev.c:6809 handle_softirqs+0x318/0xc60 kernel/softirq.c:596 __do_softirq+0x14/0x20 kernel/softirq.c:630 Freed by task 5826: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:245 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0x118/0x314 mm/slub.c:3709 kfree_skbmem+0x10c/0x198 net/core/skbuff.c:-1 __kfree_skb net/core/skbuff.c:871 [inline] consume_skb+0xa8/0x104 net/core/skbuff.c:1035 packet_rcv+0x130/0x1100 net/packet/af_packet.c:2280 dev_queue_xmit_nit+0x91c/0x994 net/core/dev.c:2366 xmit_one net/core/dev.c:3691 [inline] dev_hard_start_xmit+0xf8/0x8cc net/core/dev.c:3711 sch_direct_xmit+0x210/0x474 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3932 [inline] __dev_queue_xmit+0x13bc/0x3118 net/core/dev.c:4337 dev_queue_xmit include/linux/netdevice.h:3051 [inline] neigh_hh_output include/net/neighbour.h:529 [inline] neigh_output include/net/neighbour.h:543 [inline] ip_finish_output2+0xb98/0x109c net/ipv4/ip_output.c:228 __ip_finish_output+0x1b0/0x448 net/ipv4/ip_output.c:-1 ip_finish_output+0x40/0x264 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip_output+0x3c8/0x568 net/ipv4/ip_output.c:434 dst_output include/net/dst.h:453 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0xc84/0x1674 net/ipv4/ip_output.c:538 ip_queue_xmit+0x5c/0x7c net/ipv4/ip_output.c:552 __tcp_transmit_skb+0x17d8/0x2b88 net/ipv4/tcp_output.c:1405 __tcp_send_ack+0x23c/0x4e8 net/ipv4/tcp_output.c:4059 tcp_send_ack+0x4c/0x68 net/ipv4/tcp_output.c:4065 __tcp_ack_snd_check+0x3b4/0x848 net/ipv4/tcp_input.c:5626 tcp_ack_snd_check net/ipv4/tcp_input.c:5672 [inline] tcp_rcv_established+0xad8/0x1d20 net/ipv4/tcp_input.c:6116 tcp_v4_do_rcv+0x38c/0xa7c net/ipv4/tcp_ipv4.c:1684 tcp_v4_rcv+0x1f2c/0x24cc net/ipv4/tcp_ipv4.c:2115 ip_protocol_deliver_rcu+0x350/0x778 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x250/0x488 net/ipv4/ip_input.c:233 NF_HOOK+0x2dc/0x36c include/linux/netfilter.h:302 ip_local_deliver+0x120/0x194 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:463 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0x8a8/0xb90 net/ipv4/ip_input.c:639 ip_list_rcv+0x394/0x3f0 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5662 [inline] __netif_receive_skb_list_core+0x4e8/0x67c net/core/dev.c:5710 __netif_receive_skb_list net/core/dev.c:5762 [inline] netif_receive_skb_list_internal+0x6f0/0x998 net/core/dev.c:5853 gro_normal_list include/net/gro.h:433 [inline] napi_complete_done+0x258/0x604 net/core/dev.c:6194 gve_napi_poll_dqo+0x120/0x1c4 drivers/net/ethernet/google/gve/gve_main.c:260 __napi_poll+0xb4/0x3f0 net/core/dev.c:6628 napi_poll net/core/dev.c:6695 [inline] net_rx_action+0x514/0xb18 net/core/dev.c:6809 handle_softirqs+0x318/0xc60 kernel/softirq.c:596 __do_softirq+0x14/0x20 kernel/softirq.c:630 The buggy address belongs to the object at ffff0000f88b0000 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 0 bytes inside of 240-byte region [ffff0000f88b0000, ffff0000f88b00f0) The buggy address belongs to the physical page: page:000000006f32ea5a refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1388b0 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 0000000000000000 dead000000000001 ffff0000c086c180 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f88aff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000f88aff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000f88b0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f88b0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff0000f88b0100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ================================================================== syz.6.302: attempt to access beyond end of device loop6: rw=0, sector=1056, nr_sectors = 8 limit=16